This invention relates to an actuator device for a distribution valve provided on a container containing a product to be distributed, especially a pressurised aerosol, the valve comprising a tubular push-rod.
It is well known to use devices of this type, in which an element provided with a projection acts as a lever on the distribution valve comprising a tubular push-rod.
FR-A-2 113 376 describes an actuator device for controlling the delivery of a material from a pressurised container provided with an upper opening formed by a valve seat, the seat being fixed to the opening of the container by a mounting flange or a rolled seal. This device comprises a lever formed in one piece provided at one end with a surface that can be engaged by one finger of the operator and at the other end with a flexible clip which clips on to the flange. Between these two ends the lever comprises a projection coming to rest against the end of the tubular push-rod of the valve. The clip and the corresponding flange portion form the fulcrum of the lever. By virtue of its design, the lever pivots substantially about an axis orthogonal to the longitudinal axis defined by the tubular rod. This design has several disadvantages. Firstly, the zone in which the force is applied has a small angular range and it is necessary to apply one finger to the zone provided to this end, which is of modest dimensions. In addition, the possibility of extending the lever action is limited precisely by the design of the device, as the fulcrum of the lever is situated approximately on the flange of the closure seat of the device, while the other end preferably does not extend beyond the overall radial dimensions of the container for reasons of space and also so that it is possible to fit a cap covering the entire device and being fixed to the container. In a device of this kind, therefore, the force to be exerted must be applied over a zone of reduced angular dimensions and, in addition, the lever action is still limited precisely by the design of the device.
GB-A-1 359 152 describes a device in which the zone in which force is applied by the user has an angular range of 360.degree., giving the user a large bearing surface and leaving him free to select the point at which the actuating force is exerted. In this device, the push-button consists of a conical surface comprising on its axis a projection which presses on the valve stem, a cylindrical skirt being integral with the said conical surface and being provided with bearing means capable of cooperating, either at the exterior or in the interior, with a stop formed by the mounting flange of the valve seat. According to the position of the actuating force over the zone of application, a lever system is formed, the fulcrum of which is situated on the mounting flange, this fulcrum being situated substantially in a plane passing through the longitudinal axis and the point of application of the force. However, in this device, as in the device of FR-A-2 113 376, the possibility of extending the lever action is limited precisely by the design of the container and, consequently, the force to be applied necessarily remains considerable.
In order to reduce the force to be applied, it has been proposed to reduce the force of the valve spring. However, in this case, the long-term tightness of the valve becomes insufficient.